The present invention relates to foamed cementitious compositions and, more particularly, to such compositions containing a large amount of air which appreciably reduces the density of the resulting cellular product.
The addition of relatively small amounts of air to portland cement compositions is known in the art. The term "air entrained" is used to refer to concrete having about 6% of occluded air by volume of the finished product. Such products are made with the aid of an air entrainment additive introduced during grinding of the cement clinkers or by addition to the processing water. The purpose of air entrainment is to improve the freeze-thaw stability of the product. There would be no need to practice such air entrainment if the portland cement had been formulated with air-containing lightweight aggregate as in the present invention.